InterviewSolution
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InterviewSolution
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Solve by substitution method : 2x + 3y =9 ; 4x+ 6y =18 |
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Answer» Step 1: 2x+3y=9 ..............(eqn 1) 4x-6y=18 ............(eqn 2)divide equation 2 by 2 on both sides, we get: 2x - 3y = 9 2x = 9 + 3y x = (9+ 3y)/2 ..........(eqn 3) step 2:now put the value of x (from equation 3) in equation 1, we get: 2((9+ 3y)/2) + 3y = 9 (9 + 3y) +3y = 9 9 + 6y =9 6y = 9-9 6y = 0 y = 0 .........................(eqn 4) step 3:Now put the value of y = 0 (from equation 4) in equation 3, we get x = (9+ 3(0))/2 x = 9/2 x = 4.5 .......................(eqn 5)so the answer is x = 4.5 and y = 0. step 4:Verification:to verify the answer we can put these values of x and y in any one of the equation 1 or equation 2.put x = 4.5 and y = 0 in equation 1, we get 2x+3y=9 2(4.5) + 3(0) = 9 9 + 0 = 9 9 = 9 L.H.S. = R.H.S. Step 1: 2x+3y=9 ..............(eqn 1) 4x-6y=18 ............(eqn 2)divide equation 2 by 2 on both sides, we get: 2x - 3y = 9 2x = 9 + 3y x = (9+ 3y)/2 ..........(eqn 3)\xa0step 2:now put the value of x (from equation 3) in equation 1, we get: 2((9+ 3y)/2) + 3y = 9 (9 + 3y) +3y = 9 9 + 6y =9 6y = 9-9 6y = 0 y = 0 .........................(eqn 4)\xa0step 3:Now put the value of y = 0 (from equation 4) in equation 3, we get x = (9+ 3(0))/2 x = 9/2 x = 4.5 .......................(eqn 5)so the answer is x = 4.5 and y = 0.\xa0step 4:Verification:to verify the answer we can put these values of x and y in any one of the equation 1 or equation 2.put x = 4.5 and y = 0 in equation 1, we get 2x+3y=9 2(4.5) + 3(0) = 9 9 + 0 = 9 9 = 9 L.H.S. = R.H.S.It means our answer is right. |
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